#include <sys/time.h>
#include <time.h>

double get_time(void)
{
    static struct timeval last_tv, tv;
    static int first = 1;
    static double res = 0;

    if (first) {
        gettimeofday(&last_tv, NULL);
        first = 0;
        return 0;
    } else {
        gettimeofday(&tv, NULL);
        res += tv.tv_sec - last_tv.tv_sec;
        res += (tv.tv_usec - last_tv.tv_usec) / 1000000.0;
        last_tv = tv;

        return res;
    }
}
